Liquid Crystal Display Parallel Polarizers Wave Plate
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Liquid crystal displays face a size limitation due to the width of polarizer raw materials, leading to restricted product sizes and uneven polarization caused by transverse stretching of polyvinyl alcohol films.
Innovation Solution
The absorption axes of the upper and lower polarizers are set parallel to each other, with a wave plate positioned between the upper polarizer and the liquid crystal panel to rotate linear polarization by 85 to 95 degrees, enhancing the front contrast ratio by reducing black luminance from side light scattering.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If transverse stretching of polyvinyl alcohol films is used to create polarizers, then polarization function is achieved, but size limitation and uneven polarization occur
Solution Approach 1:
Instead of stretching the PVA film transversely to create polarization, the patent applies a longitudinal stretching method that stretches the film in the direction of the absorption axis. This inversion of the stretching direction resolves the contradiction by enabling larger polarizer sizes while maintaining uniform polarization, as the longitudinal stretching prevents the transverse unevenness that occurs with conventional transverse stretching methods
2Illumination intensity
If wave plate is positioned between lower polarizer and liquid crystal panel, then polarization rotation is achieved, but front contrast ratio is reduced due to side light scattering
Solution Approach 1:
The patent introduces a polarizer rotation layer as an intermediary component between the upper polarizer and the liquid crystal panel. This intermediate layer rotates the polarization direction of light by 85-95 degrees, which mediates the interaction between the polarizer and the liquid crystal, thereby improving the front contrast ratio by reducing the harmful effect of side light scattering while maintaining the necessary polarization rotation function
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This configuration increases the front contrast ratio significantly by minimizing black luminance and effectively addressing the size limitations of polarizers, while maintaining uniform polarization.
Implementation Method 1
a wave plate is provided between the upper polarizer and the liquid crystal panel, which rotates linear polarization at 85 to 95 degrees
Implementation Method 2
the refractive anisotropy means that a refractive index varies depending on the long axis and short axis directions of the liquid crystal, which causes a polarization state to be changed because the refractive index felt varies according to a direction when light passes through the liquid crystal molecules
Implementation Method 3
a polarizer is located at each of upper and lower portions of the liquid crystal panel and the polarizer transmits the light a polarization component, which coincides with a transmission axis determines a transmission degree of light
Data Source
Figure 1~2
Figure 3~4
Figure 5
AI summary
The present application relates to a liquid crystal display comprising: an upper polarizer; a lower polarizer; and a liquid crystal panel provided between the upper polarizer and the lower polarizer, in which the upper polarizer and the lower polarizer are provided such that the absorption axes thereof are parallel to each other, a wavelength plate is comprised between the upper polarizer and the liquid crystal panel, which rotates linear polarized light at 85 to 90 degrees, and the liquid crystal panel is a horizontally aligned liquid crystal mode.